This application relates to multi layer thermoplastic polymer alloy compositions including one or more tie-layers. This application further relates to methods of manufacturing such multi layer thermoplastic polymer alloy compositions.
Thermoplastic polymer alloy compositions have been developed to replace polyvinyl chloride for the fabrication of many articles. In the automotive field, thermoplastic polymer alloy (hereinafter TPA) compositions have been used for the fabrication of articles such as interior sheathing, including instrument panel skins, door panels, air bag covers, roof liners, and seat covers. In these applications, the interior sheathing includes a sheet or skin (hereinafter skin) made of the TPA composition.
The bottom surface of the skin is commonly adhered to a layer of foam padding, typically urethane foam. Similarly, the top surface of the skin is commonly painted to provide a desired appearance and scuff resistance. Prior to applying either the layer of foam or paint, the top and bottom surfaces of the skin are primed to increase adhesion with the foam and/or the paint.
The layer of foam padding is adhered to the skin by, for example, a foam-in-place process. During such a foam-in-place process, the skin is placed on mold cavity of a molding tool and the foam is introduced into the molding tool to fill the gap between the skin and a plastic retainer which is pre-inserted into the mold core.
A multi layer thermoplastic polymer alloy is provided. The multi layer alloy includes a skin of thermoplastic polymer alloy having non-polar segments and a tie-layer having non-polar segments and polar functional groups. The non-polar segments of the tie-layer are bondable with the non-polar segments of the thermoplastic polymer alloy skin. Similarly, the polar functional groups of the tie-layer are bondable or reactable with a surface layer.
An interior sheathing for a vehicle is provided. The sheathing includes a multi-layer skin having a first layer and a second layer, and a layer of urethane foam. The first layer of the multi-layer skin is a layer of thermoplastic polymer alloy. The second layer of the multi-layer skin is a tie-layer. The thermoplastic polymer alloy layer has non-polar segments on a first side and a second side. The tie-layer has non-polar segments and polar functional groups. The non-polar segments of the tie-layer are bonded with the non-polar segments of the first side of the thermoplastic polymer alloy. The polar functional groups of the tie-layer are bonded to or reacted with the layer of urethane foam.
A method of forming a multi layer thermoplastic polymer alloy is provided. The method includes providing a thermoplastic polymer alloy skin, providing a tie-layer, disposing the tie-layer on a lower surface of the thermoplastic polymer alloy skin, and exposing the thermoplastic polymer alloy skin and the tie-layer to heat and pressure. The thermoplastic polymer alloy skin has non-polar segments. The tie-layer has non-polar segments and polar functional groups. The non-polar segments of the tie-layer are bondable with the non-polar segments of said thermoplastic polymer alloy skin. Similarly, the polar functional groups of the tie-layer are bondable or reactable with a layer of foam.
The above-described and other features and advantages of the present application will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims.